Name: weightlessness and einstein’s equivalence
Uploaded: 2023-04-30T11:07:46.000Z
Duration: 1 min 18 s
Channel: JoVE

K12 Standards

Virginia  Standards of Learning

HIgh School

Physics

PH.9

PH.9.c

Principle of Equivalence

Un transbordador espacial que orbita la Tierra está en movimiento de caída libre, limitado por la fuerza gravitacional de la Tierra. Sin embargo, un astronauta dentro del transbordador espacial siente ingravidez, como si ninguna fuerza estuviera actuando sobre él.
Supongamos que el transbordador espacial acelera hacia arriba a 9,8 m/s2; el suelo de la sala del transbordador espacial se moverá hacia el astronauta flotante. Sin embargo, para el astronauta, parece como si estuviera acelerando hacia abajo hacia el suelo del transbordador espacial a 9,8 m/s2.
Para él, la aceleración crea una atracción en el transbordador espacial, similar a la gravedad en la superficie de la Tierra. Sentado dentro de la sala cerrada del transbordador espacial, el astronauta no puede distinguir si está en la Tierra o acelerando en el espacio.
Einstein, por lo tanto, afirmó que no hay diferencia entre un campo gravitatorio uniforme y una aceleración uniforme en ausencia de gravedad. A esto se le conoce como el Principio de Equivalencia.
Concluyó que la gravedad no es una fuerza entre dos masas, sino que surge de la interacción de la materia y el espacio.

principio de equivalencia

Según Albert Einstein (1897-1955), caer libremente y sentirse sin peso están intrínsecamente relacionados. Si una persona estuviera en caída libre bajo la gravedad, por ejemplo, cayendo hacia la Tierra desde un avión, se sentiría completamente sin peso. De manera similar, una persona que desciende en un ascensor puede sentirse parcialmente sin peso. En términos generales, se asume que un objeto en un campo gravitatorio uniforme y un objeto sometido a una aceleración constante en ausencia de gravedad están bajo las mismas condiciones experimentales (es decir, ningún experimento puede diferenciar entre los dos escenarios). A esta afirmación se le llama principio de equivalencia. El principio aborda una suposición fundamental de la ley de gravitación de Newton: se asume que las masas que determinan la fuerza de atracción gravitatoria entre dos objetos son las mismas masas que determinan su reacción a las fuerzas a través de las leyes de movimiento de Newton. Sin embargo, estas dos masas, a veces llamadas masa gravitatoria y masa inercial, pueden ser diferentes en la práctica. Las consecuencias de asumir que son iguales, y por lo tanto los resultados de combinar la ley de gravitación de Newton con las leyes de movimiento de Newton, concuerdan con los experimentos. En otras palabras, la suposición resulta ser experimentalmente válida. Sin embargo, no se entiende la razón de esta consecuencia. Según el principio de equivalencia, esto no es una coincidencia. Fundamentalmente, la aceleración uniforme y la gravedad son lo mismo. Al relacionar la aceleración uniforme con la gravedad, Einstein propuso que la gravedad no es una fuerza entre dos objetos. En cambio, es un efecto de los dos objetos sobre el espacio-tiempo que los rodea, lo que a su vez determina su dinámica. Estas ideas las volvió matemáticas en su teoría general de la relatividad en 1915. Este texto está adaptado de <a href="https://openstax.org/books/university-physics-volume-1/pages/13-7-einsteins-theory-of-gravity">Openstax, University Physics Volume 1, Section 13.7: Einstein's Theory of Gravity.</a>

Principio de Equivalencia

Según Albert Einstein (1897-1955), la caída libre y la sensación de ingravidez están intrínsecamente vinculadas. Si una persona estuviera en caída libre bajo la gravedad, por ...

Education

Educación

JoVE Core

Física

Unit 1

Unidad 1

Gravitation

Gravitación

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

weightlessness and einstein’s equivalence

Weightlessness and Einstein’s equivalence principle are closely connected in gravity. A person in free fall under gravity, such as someone diving toward Earth from an airplane, would feel completely weightless. A person descending in a lift may feel partially weightless.

The principle of equivalence says that an object in a uniform gravitational field and an object accelerating at a constant rate with no gravity are under the same experimental conditions. In other words, no experiment can tell the two situations apart. This idea links gravity with uniform acceleration.

The principle also addresses a key assumption in Newton’s law of gravitation. It assumes that the mass that creates gravitational attraction is the same as the mass that responds to force in Newton’s laws of motion. These are sometimes called gravitational mass and inertial mass. They can be different in practice, but the results from combining Newton’s law of gravitation with Newton’s laws of motion still match experiments.

Einstein argued that this agreement is not a coincidence. He proposed that gravitation is not simply a force between two objects. Instead, it is an effect of those objects on the space-time around them, which then shapes their motion. He turned these ideas into mathematics in his general theory of relativity in 1915.

Weightlessness and Einstein’s Equivalence

gravitation

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principle of equivalence

Weightlessness and Einstein’s equivalence principle are closely connected in gravity. A person in free fall under gravity, such as someone diving toward Earth from an airplane, would feel completely weightless. A person descending in a lift may feel partially weightless. The principle of equivalence says that an object in a uniform gravitational field and an object accelerating at a constant rate with no gravity are under the same experimental conditions. In other words, no experiment can tell...

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key terms and concepts

Learn how free fall, weightlessness, and constant acceleration connect in Einstein’s equivalence principle and why it led to general relativity.

Weightlessness and Einstein’s Equivalence | JoVE K12

physics

JoVE Core Física presenta la teoría y la aplicación de conceptos físicos fundamentales, como la cinemática, dinámica, mecánica de fluidos, estática, ondas y acústica, mediante animaciones audiovisuales concisas y fáciles de entender. Además, los vídeos de científicos en acción muestran la aplicación de los conceptos relacionados en experimentos de investigación clásicos y originales, realizados en laboratorios de todo el mundo.

Alabama Course of Study Science

9-12

Earth and Space Science

Earth's Place in the Universe

9-12.ESS.1.3

Florida Department of Education

High School

SC.912.E.5

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SC.912.E.5.10

Georgia Standards of Excellence

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PH.9.b

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PH.9.d

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The student will investigate and understand that extremely large and extremely small quantities are not necessarily described by the same laws as those studied in Newtonian physics. Topics, such as these listed, may be included. solid state physics;

PH.9.e

The student will investigate and understand that extremely large and extremely small quantities are not necessarily described by the same laws as those studied in Newtonian physics. Topics, such as these listed, may be included.

Weightlessness and Einstein’s Equivalence

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